Good question.
As a premise, I say that every opinion is obviously subjective.
What I consider "wonderful", may be "ugly" for someone else.
Anyway, I don't know if there's a website with such a comparison, but it's easy to make it: just do a search on Flickr or any other photo sharing service of the same subject with the same camera and gear.
For example, take:
flickr.com/photos/anna_abramova/2351141120/
flickr.com/photos/chanc/4757005099/
(sorry, can't post more than one link for this stupid spam filter)
It's the Colosseum (an Italian monument, if you live on the Moon and don't know it :).
The first was taken with a Canon 5D, one of the best cameras on the market, the second with the less powerful 30D. But, you see, the second photo is much more interesting and visually pleasing.
Or even, you can see here another interesting and suggestive shot.
And, believe it or not, it was taken with an Apple iPhone. That is just a cellphone, after all.
So, in my opinion, you can take beautiful shots with simple gear and ugly ones with top-rated cameras.
It's the photographer that makes the photo, not viceversa.